There are known mixing and kneading devices of the general type above-referred to which comprise a power drive means including an electric motor with a gearing coupled thereto and a receptacle for a supply of the material to be mixed and kneaded therein. Mixing and kneading means disposed in the receptacle are journalled in the end walls thereof and secured to the gearing by suitable releasable fastening means. The receptacle is composed of two superimposed parts and constitutes, together with the power drive means, a closed-off work unit. This working unit is joined to the power drive means by releasable fastening means. Mixing and kneading devices of the general type above-described are described, for instance, in German Pat. No. 1,195,722. They have been found generally satisfactory, particularly for use in testing or research and development laboratories since the mixing and kneading receptacle when ready to be emptied can be detached from the device. The detached receptacle can then be replaced by another receptacle which is already charged with material to be mixed and kneaded. It is also advantageous that the power drive means needs to be stopped by only a short time before it can be restarted after attachment of another receptacle containing new material to be processed.
However, the emptying, cleaning and the generally used powdering of the receptacle is quite time consuming; the more so as many of the materials as are mixed and kneaded in such devices tend to have a high viscosity and/or to be sticky. Moreover, with many of the types of materials which are processed in mixing and kneading devices of the kind here involved complete emptying and cleaning of the receptacle and also of the mixing and kneading tools within the receptacle require a complete disassembly of the device.
With mixing and kneading devices of the general type herein-referred to as now known, complete disassembly of the receptacle is rather complex and time-consuming since the two parts of the receptacle are joined by a substantial number of screws, which must be unscrewed by appropriate tools such as screwdrivers. Such delay before the receptacle is ready for emptying and cleaning and subsequent recharging is disadvantageous because many of the materials to be processed in these devices harden rather rapidly. Accordingly, emptying and cleaning should be effected as quickly as possible upon completion of a mixing and kneading operation. It has been found in practice that in such cases the time required for removing the screws used for joining the two parts of the receptacle is long enough to permit hardening of the mixed and kneaded material to such an extent that a thorough emptying and cleaning of the receptacle is at best difficult and sometimes virtually impossible.